Scada system aids North Sea fiscal metering

Edited by the Engineeringtalk editorial team May 28, 2004

EnCana's Scott Platform in the North Sea is leading the way in fiscal metering of oil and gas as a result of installing a new PC based flow metering computer system.

EnCana's Scott Platform in the North Sea is leading the way in fiscal metering of oil and gas as a result of installing MeterNet, a technically advanced, PC based flow metering computer system developed by Stephen Gillespie Consultants (SGC).

Central to the operation of MeterNet is Meteor, a metering supervisory computer which deploys the high levels of functionality and redundancy provided by CitectScada to deliver highly efficient remote monitoring, control, reporting, and archiving of metering activities with round-the-clock reliability.

MeterNet brings a new dimension to metering computer system design, introducing modern technology to replace the conventional system structure of proprietary flow computers and associated database computers.

The system utilises the metering principles and associated standards mandatory for fiscal metering, but employs PC technology for all computational functions and distributed I/O systems as the interface to all field instrumentation and equipment.

The MeterNet system is a two-tier design where the task of gathering real time data from the distributed I/O systems is performed the SGC Integrator (the virtual flow computer) and all HMI and metering supervisory functions are provided by the Meteor.

Wilson Burt, Sales Manager for SGC explains:, "To meet all the metering supervisory computer requirements for a MeterNet solution we required a Windows based system that provides true dual redundancy, has OPC clients and servers as well as comprehensive reporting and archiving facilities".

"CitectScada provides all this within the standard product and therefore fits well with our needs".

"The package is easy to use, requires a minimum of engineering time to integrate and can be configured to produce reports triggered by time or event".

CitectScada is used extensively in the oil and gas industries worldwide, its flexibility, speed of operation and ability to handle from the smallest to the largest systems (450,000-plus I/Os), enabling it to perform remote monitoring and control of pipelines, tank farms, natural gas and liquid hydrocarbon extraction sites, and also offshore platforms.

The system is designed with DCS style multilevel redundancy, which is easy to configure and can be incorporated at all levels.

The significance of this for the user is the ability to tolerate hardware failure anywhere in a system, with no loss of functionality, performance, communication or system reliability.

The CitectScada system provided by SGC for the Scott Platform provides a common HMI for the entire metering system, with comprehensive displays and the facility for modification of instrument configurations.

The system also allows operators to perform remote operation of field equipment (such as valves) in singular or sequential routines.

Two other major functions of the Windows-based Citect package are retrieving metering parameters from the SGC Integrator - a suite of object-based software configured to provide flow measurement calculations, and formatting metering data into reports.

This data, which can have access controlled by passwords and a multilevel security system, is subsequently archived by the Scada system into a historical database for future use.

Also archived is data regarding metering and alarm reports.

These are produced instantaneously as required and are available from any authorised PC terminal attached to the Meteor/CitectScada system.

On the Scott platform the main operator remote terminal is provided by a remote client PC situated in the CCR (central control room).

This provides the CCR operator with full system access and control.

The system can also be accessed from EnCana's offices in Aberdeen, providing the onshore engineer the benefits of full system emulation via his existing desktop PC.

In addition to viewing of live data and trends, local saving and printing of historical reports is also provided.

Although new to the UK market, CitectScada is already the HMI/Scada manufacturing automation system of choice for many successful global manufacturers.

These include Alcoa, General Motors, NASA, Urenco, Baoshan Steel, BHP Billiton, Pratt and Whitney, BP Solar, WMC Resources, BMW, Nestle, Mars Confectionery and Shell Oil, to name but a few.